The ATUM plugin currently has a lengthy process to manage stock. While it may not seem much of a process to small stores, imagine the ones having 1000s of products. It then becomes a task to search, update inventory or log the activity.
Also, imagine a new-user onboarding the ATUM plugin. The setting up for the inventories across so many products becomes a tiring job.
In comes, the manual quick add/edit/remove inventory controller for Multiple Inventory add-on. It could be a little dashboard widget or a page. It has this search box where one simply inputs/scans the product SKU and the widget displays all the multiple inventories (if any) for the particular sku.
Once the results are out, one can "add/create" a new inventory, "update" the existing inventory (add, remove stock) or simply write-off an inventory.
It is a hell lot better than going to stock central and loading everything up, searching through the very large list of catalog. Also, such a widget makes functioning flexible and efficient. The time taken to perform these actions is relatively short for humans and also the database.
It is worth noting, that stock central currently doesn't have such quick functionality for creating/writing off multiple inventories. And given its importance, it deserves to have its own Muti-Inventory stock central/controller.